Those unflattering fluorescent supermarket lights do have one benefit, suggests a new study: they help spinach produce more nutrients. The study, published in the Journal of Agricultural and Food Chemistry, revealed that spinach stored continuously under the light for as little as three days boasted higher levels of vitamin C and preserved levels of K, E, folate and the carotenoids lutein and zeaxanthin.

The lights enhance nutrient levels by encouraging photosynthesis—the process by which plants use energy from the sun to create food and compounds that protect them. A side benefit for us: those same nutrients that protect plants protect us too. For example, carotenoids help shield a plant from sun damage. And, similarly, eating carotenoid-rich foods helps to protect our skin against sunburn, explains Gene Lester, M.S., Ph.D., plant physiologist with the USDA’s Agricultural Research Service and lead author of the study.